A Scotland yard inspector (Hugh Williams) is faced with a spree of unsolved murders in which the victims are found drowned and abandoned in the revered Thames river in London. When the body count has reached the fifth corpse, he is joined by a wise cracking Chicago detective (Edmon Ryan) fresh from America. Apparently, the home for the blind in which the maddened Dr. Orloff (Bela Lugosi) holds the insurance policies for all of the deceased, sparks an unexplainable coincidence, especially with the shoot ’em first, ask questions later American cop. The light begins to illuminate the far less than perfect past of Feodor Orloff, a former doctor driven out of his position and profession by his colleagues, deemed as insane as a result of his unorthodox thoughts and practices, and their relation to modern science. It seems the policy holders of these insurance contracts have made a large charitable donation at the good doctor’s request, eventually leading to their suspicious demise. Orloff’s mind controlled hulking assistant (Wilfred Walter) does his bidding by sending them to their watery graves, until he realizes during the attempted attack on a young lady (Greta Gynt) whose father was one of the victims, that Orloff himself has killed his best friend for knowing the truth behind his evil plot. Upon the doctors return a terrible struggle ensues, and Orloff plummets to his death into the arms of the very body of murky water to which he has sent his previous victims, leaving his misshapen blind assistant to die from the gunshot at Orloff’s hand.
Originally Entitled, “The Dark Eyes of London”, this 1939 rendition of the 1924 story by Edgar Wallace, had been the very first British film ever to be given an “H” rating for horrific (too frightening for those younger than sixteen years of age). While portraying the voice of Dearborn, Bela’s voice had been dubbed by O. B. Clarence. The final scene involving Orloff’s death had been a difficult task. A seven-foot deep tank had been filled with muck to resemble river mud. A crew member was lowered into the concoction to film the scene secured by a chain in case of being sucked into the mire. Bela himself had been submerged up to his neck with weights on his ankles to keep his body sunken below the simulated river mix. The film had been rereleased in March of 1940 as “The Human Monster”.